1. Field of the Invention
This invention relates to a catalyst for gas/liquid reactions and a process for gas/liquid reactions, more particularly, to a catalyst suitable for application to a process for enriching heavy water by the isotopic exchange reaction between water and hydrogen gas and to a process for gas/liquid reactions by using such a catalyst.
2. Description of the Prior art:
In a process for producing heavy water by the isotopic exchange reaction between water and hydrogen gas, a catalyst having water repellency has been used to obtain an increased rate of reaction. There have been proposed a process in which a hydrophilic catalyst is coated with polytetrafluoroethylene to render the catalyst water-repellent (U.S. Pat. No. 3,981,976) and a process in which a water-repellent organic polymer is allowed to support a catalytically active component such as platinum, rhodium or nickel (U.S. Pat. No. 4,025,560). Most of such catalysts are prepared by embedding a catalytically active component into voids of a porous carrier having the form of sphere or cube measuring several millimeters in side by impregnation or other methods. For example, catalysts prepared by impregnating a carrier consisting of 3 mm-side cubes of porous polytetrafluoroethylene with platinum were disclosed in the above-mentioned U.S. Pat. No. 4,025,560. These catalysts are packed into a reacton tube, through which gas and liquid are passed. The gas and the liquid are brought into contact with the surfaces of the spherical or cubic form catalyst and establish three-phase interfaces.